Neodiaptomus intermedius n. sp. (Calanoida: Copepoda) from South India

A new species of Neodiaptomus, N. intermedius n. sp. is described and illustrated. It is compared with related species of the strigilipes — physalipus species group.     

Autoradiographic detection of the earliest stage of [3H]-uridine incorporation into the cow embryo

Cow embryos, obtained from superovulated heifers on days 3 and 4 after oestrus, were cultured for 20 min in Ménézo's complete culture medium (B2), enriched with 200 microCi/ml of 5-[3H]-uridine. Semi-thin Epon sections of this material were investigated by autoradiography for sites of RNA synthesis. It was found that 5-[3H]-uridine was incorporated into the nucleoplasm and nucleoli only at the end of the 8-cell stage. This suggested that synthesis of hnRNA and rRNA occurred from this stage onwards. Ultrastructural studies were performed on these embryos as well as on other non-incubated 4-cell embryos recovered on day 2. The transformation of dense fibrillar primary nucleoli into functional reticulated nucleoli appeared sooner in the development of cow embryos than in other mammalian species hitherto studied and took place generally during the 8-cell stage. An unusual step in this transformation was represented by the development of a single vacuole in nucleoli at the beginning of this stage (day 3 post-oestrus).     

Proacrosin and the differentiation of the spermatozoa

Using the indirect immunofluorescence staining technique, the occurrence and localization of proacrosin, the zymogen form of acrosin, was studied during spermatogenesis in the bull, ram, boar and rabbit. Proacrosin staining was demonstrable for the first time in the early haploid spermatid and increased with the differentiation of the spermatid to spermatozoon. The spermatozoon is covered by a cap-like structure of uniform fluorescence corresponding to the acrosomal compartment of the male gamete. No fluorescence could be found in diploid spermatogenic cells, i.e., in spermatogonia and spermatocytes. An identical developmental pattern of proacrosin was observed with the indirect immunoperoxidase staining technique. However, with this staining technique a distinct distribution of proacrosin staining was observed in the acrosome of epididymal and ejaculated spermatozoa of the bull, ram, boar, rabbit and man. Proacrosin seems to be distributed in the acrosome in granules rather than in the homogeneous form, as was indicated by the results of indirect immunofluorescence staining.     

Elektronenmikroskopische Untersuchungen an den Hüllen der Oozyten und Eier des Flussbarsches Perca fluviatilis

Zusammenfassung Die Hüllen von Oozyten und reifen Eiern des Fußbarsches wurden licht- und elektronenmikroskopisch untersucht. In Oozyten vor der Bildung der Zona radiata sind die meisten der keulenförmigen Mikrovilli gerade auf die Follikelzellen ausgerichtet. Gelegentlich verlaufen Mikrovilli auch parallel zur Oozytenoberfläche. Die Zona radiata reiferer Eizellen besteht aus zwei Schichten, der elektronendichten Zona radiata externa und der weniger dichten Zona radiata interna. Während die erstere aus einem hochorganisierten Material besteht, ist die letztere aus einer Substanz von geringerer Dichte zusammengesetzt. In der Matrix der Zona radiata interna liegen unregelmäßig angeordnete flaschenbürstenähnliche Einschlüsse. Nach Kontrastierung mit l%iger Phosphorwolframsäure und 0,5% igem Uranylazetat sind feine Fibrillen in der Matrix nachweisbar. Die Zona radiata externa ist außen von einer Gallerthülle umgeben. Sie ist etwa fünfmal so stark wie die gesamte Zona, radiata. Diese Gallerthülle besteht aus homogenem Material von geringerer Dichte. Nach Anfärbung mit 0,2%-igem Rutheniumrot färbt sich diese Schicht intensiv rot. Daraus läßt sich auf das Vorhandensein von sauren Mukopolysacchariden schließen. In der Gallerthülle liegen elektronendichte Körnchen, in denen sich bei hoher Auflösung eine hochorganisierte, kristalloide Struktur nachweisen läßt. Die Gallerthülle wird von den zytoplasmatischen Fortsätzen der kegelförmigen Follikelzellen durchdrungen. Diese Fortsätze gehen in Ausläufer über, die in die Porenkanäle der Zona radiata eindringen. In einigen Fällen umhüllen die Ausläufer der Follikelzellen die Mikrovilli der Oozyte vollständig. Normalerweise liegen die Mikrovilli und die Ausläufer aber deutlich voneinander getrennt. Die Mikrovilli enden entweder direkt an der Zellmembran der Follikelzellen oder sie dringen tief in Membraneinstülpungen ein. Mikrovilli und die Ausläufer der Follikelzellen befinden sich in den Porenkanälen fast reifer Eier. Kurz vor der Ovulation werden sie wahrscheinlich zurückgezogen. Die Porenkanäle reifer Barscheier sind im äußeren Drittel der Zona radiata interna verschlossen.

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Summary The envelope of oocytes and mature eggs of the perch was examined by light and electron microscope. In oocytes before the formation of the zona radiata most of the clubshaped microvilli project straightly towards the follicular cells. Some, however, run parallel to the oocyte surface. The zona radiata of more mature oocytes consists of the electron dense zona radiata externa and the less electron dense zona radiata interna. While the former consists of a highly organized material, the latter is composed of a substance of low density, with the exception of a few brush-shaped inclusions which are scattered irregularely within the matrix of the zona radiata interna. After treatment with 1% phosphotungstic acid and 0.5% uranyl acetate tiny fibres become visible. External to the zona radiata externa the oocytes are enveloped by a jelly layer, about five times as thick as the zona radiata. The jelly layer appears to consist of a rather homogeneous material of low density. After treatment with a solution of 0,2% ruthenium red the jelly layer is stained intensely red, suggesting the presence of acidic mucopolysaccharides. Within the matrix of the jelly layer are embedded electron dense granules of unknown function. At high resolution they reveal a well organized, crystalloid structure. The jelly layer is penetrated by cytoplasmic processes of the cone-shaped follicular cells. These processes develop extensions which enter the pore canals of the zona radiata. In some cases these extensions envelope the microvilli of the oocytes completely. But normally the microvilli and the extensions are clearly separated. The microvilli make either direct contact with the membrane of the follicular processes or penetrate deeply into membrane interdigitations. Microvilli together with follicular extensions are present in the pore canals of almost mature eggs. They seem to be withdrawn just before ovulation. The pore canals of the zona radiata are partly closed in mature eggs.

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Ich verdanke die Anregung zu dieser Arbeit einer Diskussion, die ich mit Herrn Prof. Dr. E. A. Arndt, Rostock, anläßlich seines Vortrages am 21. Februar 1966 in Kiel führte.

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Untersuchungen mit Unterstützung durch die Deutsche Forschungsgemeinschaft. Herrn Prof. Dr. O. Moritz, Institut für Pharmakognosie, danke ich für die Möglichkeit, das Elektronenmikroskop seines Institutes zu benutzen. Frau R. Bardenhewer, geb. Schmidtke, danke ich für die Hilfe bei der Präparation und für die Anfertigung der photographischen Vergrößerungen.     

PQQ, the elusive coenzyme

The recently discovered redox coenzyme, PQQ (methoxatin), is widely distributed. Quantitation of protein-bound PQQ has been difficult, but unique redox cycling reactions, which reflect its striking biological properties, reveal trace amounts. PQQ is a potential target for drugs.     

The capacity of bottle-nosed dolphins for generalization according to a relative sign

In bottle-nosed dolphins by a new modification of previously suggested method, a conditioned reflex was elaborated and consolidated to a relative spatial sign--choice of always left object from two similar ones in conditions of a permanent change of place of this pair of stimuli against the background of one of the sides of an open-air cage. Specialization of the reflex was checked by presentation of a pair of stimuli under different changes of surroundings, including discordance of external orientors and also the way of stimuli presentation. Then the initial objects were substituted by others (12 pairs of stimuli) sharply differing from the initial ones by the form, size, material etc. Retention of adequate choice also at the change of the medium of stimuli presentation, testified to the ability of dolphins of abstraction and generalization by relative sign, i.e. at the choice from two objects of the type "to the right--to the left in general".     

Diurnal variation of corticotropin-releasing factor binding sites in the rat brain and pituitary

Summary 1. Corticotropin-releasing factor (CRF) is thought to be involved in the regulation of the diurnal activity of the hypothalamus-pituitary-adrenal (HPA) axis and to act as a neurotransmitter in the brain. To date it is unknown whether the binding sites of the central CRF system are subject to diurnal variations. 2. We measured the number of CRF binding sites over the course of a complete 24-hr light-dark cycle in the pituitary, amygdala, bed nucleus of the stria terminalis (BNST), cingulate cortex, visceral cortex, paraventricular nucleus of the hypothalamus, hippocampus, and locus ceruleus of rats byin vitro receptor autoradiography with iodinated ovine CRF. A 24-hr time course was also established for plasma CRF and corticosterone. 3. The diurnal pattern of plasma CRF does not correlate with the pattern of plasma corticosterone. Within the brain, CRF binding in the basolateral nucleus of the amygdala showed a U-shaped curve with maximum levels in the morning and a wide hallow between 1500 and 0100. A biphasic profile with a small depression in the afternoon and a more pronounced depression in the second half of the activity period is characteristic for the other brain areas and the pituitary. The profile for the pituitary correlates with those for the BNST and the area of the locus ceruleus. Furthermore, the diurnal pattern of CRF binding sites in the BNST correlates with that of the hippocampus, and the daytime pattern of the visceral cortex is similar to that of both the hippocampus and the BNST. 4. Since the CRF-binding profiles in the brain and the pituitary clearly differ from the profiles of both plasma CRF and corticosterone, one may assume that the diurnal pattern of central CRF binding sites is not directly coupled to the activity of the HPA axis.     

Early ordovician reefs from Argentina: Stromatoporoid vs stromatolite origin

Summary Late Arenigian biohermal reef mounds and biostromes within the shallow-marine platform facies of the upper San Juan Formation of the Precordillera (Western Argentina) represent a new Early Ordovician reef type. The meter-sized reefs are dominated byZondarella communis n.g. n. sp. The new taxon is characterized by domical, bulbous and laminar morphotypes exhibiting growth layers and thin horizontal and vertical as well as intermingled skeletal elements included within different sets. The fossil maybe compared with stromatolites and stromatoporoids but an interpretation as primitive stromatoporoids is favoured.     

A ‘Problematic fossil’ revealed:Pycnoporidium ? eomesozoicum Flügel, 1972 (Late Triassic,Tethys)—not an enigmatic alga but a strophomenid brachiopod (Gosaukammerella n.g.)

Summary The microproblematicumPycnoporidium ? eomesozoicum Flügel, 1972, from Upper Triassic reefs of the Alpine-Mediterranean region, Turkey Oman and Iran (originally interpreted as possible alga) represents the type species of a new strophomenid brachiopod genus (Gosaukammerella n.g.). The genus is characterized by a very small, millimeter-sized plano-convex shell, whose ventral valve is attached to the substratum (mainly sponges) by symmetrically arranged outgrowths developing from a pseudopunctate, lamellose foliated shell wall and composed of densely spaced subparallel ‘tubes’ comparable with productide spines secreted by papillose extensions of the mantle.Gosaukammerella seems to be the only reliable candidate for the existence of post-Paleozoic strophomenid (productid ?) brachiopods. Gosaukammerella eomesozoica is restricted to possibly cryptic, shaded reef environments inhabited predominantly by sponges serving as substrates for micromorphic brachiopods.     

Narthecium ossifragum Associated Photosensitization in Sheep in The Faroe Islands

Hepatogenous photosensitization in sheep is an important problem in various parts of the world. Most photosensitization diseases are associated with ingestion of plant or fungal toxins. The lily, Narthecium ossifragum, has long been associated with photosensitization in lambs in western Norway (Ender 1955, Flåøyen 1993) and in the northern regions of the British Isles (Ford 1964).